Java Tutorial/Spring/MethodBeforeAdvice

Implements MethodBeforeAdvice To Check Parameters

File: context.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN"
    "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
  <bean id="afterBean" class="org.springframework.aop.framework.ProxyFactoryBean">
    <property name="target">
      <bean class="MtBean">
        <property name="firstName" value="AAA"/>
      </bean>
    </property>
    <property name="interceptorNames">
      <list>
        <idref bean="nullArgumentsNotAllowedBeforeAdvice"/>
      </list>
    </property>
    <property name="proxyTargetClass" value="true"/>
  </bean>
  <bean id="nullArgumentsNotAllowedBeforeAdvice"
        class="NullArgumentsNotAllowedBeforeAdvice"/>
</beans>

Method Before Advice

File: Main.java

import java.lang.reflect.Method;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.framework.ProxyFactory;
public class Main {
  public static void main(String[] args) throws Exception {
    MessageWriter target = new MessageWriter();
    ProxyFactory pf = new ProxyFactory();
    pf.addAdvice(new SimpleBeforeAdvice());
    pf.setTarget(target);
    MessageWriter proxy = (MessageWriter) pf.getProxy();
    proxy.writeMessage();
  }
}
class MessageWriter {
  public void writeMessage() {
    System.out.println("A");
  }
}
class SimpleBeforeAdvice implements MethodBeforeAdvice {
  public void before(Method method, Object[] args, Object target) throws Throwable {
    System.out.println("Before method: " + method.getName());
  }
}